Anomalous Fermi Liquid Effects in Two-Dimensional Hubbard Model near Half-Filling : Condensed Matter: Electronic Properties, etc.

概要

論文の詳細を見る
The Landau parameters F^s_0, F^a_0, F^s_1 and F^a_1 in the two-dimensional Hubbard model are calculated by the second order perturbation method of Abrikosov-Khalatnikov. The following points are revealed as the half-filling is approached: (1) F^a_0 changes its sign from negative to positive, if the Coulomb interaction U is strong enough, i.e., U/t ≳ 2.0. This means that the spin density oscillations, zero spin-sound, can propagate there; (2) F^s_1 changes its sign from positive to negative, so that we can understand, on the basis of the anisotropic Fermi liquid theory, the behavior of the Drude weight whose magnitude decreases as the half-filling is approached even if there were no mass enhancement; (3) From the results of F^s_0 and F^a_0, it is shown that both the charge and spin susceptibility decrease rapidly close to the half-filling. The latter is regarded as the so-called spin-gap behavior.
社団法人日本物理学会の論文
2000-07-15